package edu.princeton.cs.algs4;

import edu.princeton.cs.stdlib.StdIn;

/*************************************************************************
 * Compilation: javac Shuffle.java Execution: java Shuffle < list.txt
 * 
 * Reads in a list of strings and prints them in random order. The Knuth (or
 * Fisher-Yates) shuffling algorithm guarantees to rearrange the elements in
 * uniformly random order, under the assumption that Math.random() generates
 * independent and uniformly distributed numbers between 0 and 1.
 * 
 * % more cards.txt 2C 3C 4C 5C 6C 7C 8C 9C 10C JC QC KC AC 2D 3D 4D 5D 6D 7D 8D
 * 9D 10D JD QD KD AD 2H 3H 4H 5H 6H 7H 8H 9H 10H JH QH KH AH 2S 3S 4S 5S 6S 7S
 * 8S 9S 10S JS QS KS AS
 * 
 * % java Shuffle < cards.txt 6H 9C 8H 7C JS ... KH
 * 
 *************************************************************************/

public class Shuffle {
	public static void main(String[] args) {

		// read in the data
		String[] a = StdIn.readAll().split("\\s+");
		int N = a.length;

		// shuffle
		for (int i = 0; i < N; i++) {
			// int from remainder of deck
			int r = i + (int) (Math.random() * (N - i));
			String swap = a[r];
			a[r] = a[i];
			a[i] = swap;
		}

		// print permutation
		for (int i = 0; i < N; i++)
			System.out.println(a[i]);
	}
}
